Holiday Hair: The Best Celebrity Looks

Coiffeur Giannandrea, known for teasing Drew Barrymore's strands into voluminous updos, likes the look. "Adding height to the crown can be tricky, but when done in the right proportions, it's very glamorous," he says. "A ponytail with volume on top is always stylish."

When prepping for a red-carpet event, Jessica Biel turns to Fekkai hair guru Adir Abergel. He recommends Biel's dual-texture bun—sleek in the front and messy in the back—when wearing a sparkling dress. "When hair is touchable, approachable, and a little disheveled, there's something supersexy about it," he says.